On-cell indicators require a user to press one or two buttons, wait for several seconds and then observe an indicator that shows the state of charge of the battery. This is inconvenient for the user because they must remove the batteries from the device, hold the battery, and press the button(s). The user must then reinstall the battery into the device. This is cumbersome and time consuming.
Electro-chromic displays draw very little power from the battery being tested and can therefore remain on and allow the user to just look at the battery to determine the state of charge. However, the current state-of-the-art in electro-chromic indicator technology has short operational life (less than a few weeks once activated) if it is continuously powered in the on condition.
Accordingly, a need exists for improved on-cell indicators that do not require user activation and increase the service life of the electro-chromic display.